United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued September 14, 2017 Decided February 16, 2018

No. 15-1115

SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT,

PETITIONER

v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.,

RESPONDENTS

NATIONAL ENVIRONMENTAL DEVELOPMENT ASSOCIATION'S 

CLEAN AIR PROJECT, ET AL.,

INTERVENORS

Consolidated with 15-1123

On Petitions for Review of a Final Action

of the Environmental Protection Agency

Megan E. Lorenz Angarita argued the cause for petitioner 

South Coast Air Quality Management District. With her on the 

briefs were Kurt R. Wiese and Barbara Baird.
2

Seth L. Johnson argued the cause for Environmental 

Petitioners. With him on the briefs was David S. Baron. 

Kelvin J. Dowd and Andrew B. Kolesar III were on the 

brief for amicus curiae Ventura County Air Pollution Control 

District in support of petitioner South Coast Air Quality 

Management District. 

Heather E. Gange, Trial Attorney, U.S. Department of 

Justice, argued the cause for respondents. With her on the brief 

was John C. Cruden, Assistant Attorney General at the time the 

brief was filed.

Seth L. Johnson argued the cause for Environmental 

Movant-Intervenors. With him on the brief was David S. 

Baron. 

Megan E. Lorenz Angarita, Kurt R. Wiese, and Barbara 

Baird were on the brief for amicus curiae South Coast Air 

Quality Management District in support of respondent’s 

opposition to Sierra Club’s argument regarding reasonably 

available control technology in Case No. 15-1123.

Leslie Sue Ritts was on the brief for intervenor for 

respondent National Environmental Development 

Association's Clean Air Project in support of U.S. 

Environmental Protection Agency.

Before: GARLAND, Chief Judge, ROGERS, Circuit Judge, 

and SENTELLE, Senior Circuit Judge.

Opinion for the Court filed by Senior Circuit Judge

SENTELLE.
3

SENTELLE, Senior Circuit Judge: In this consolidated 

proceeding, we consider petitions for review of an 

Environmental Protection Agency (“EPA”) final rule entitled 

“Implementation of the 2008 National Ambient Air Quality 

Standards for Ozone: State Implementation Plan Review 

Requirements,” 80 Fed. Reg. 12,264 (Mar. 6, 2015). In Case 

No. 15-1115, petitioner South Coast Air Quality Management 

District (“South Coast”) contends that the EPA incorrectly

concluded that precedent of this Court requires emissions 

reductions that demonstrate reasonable further progress all 

come from within the nonattainment area. In Case No. 15-

1123, petitioners Sierra Club, Conservation Law Foundation, 

Downwinders at Risk, and Physicians for Social Responsibility 

(Los Angeles) (“Environmental Petitioners”) contend that in 

enacting the Final Rule, the EPA acted arbitrarily and 

capriciously in its revocation of 1997 National Ambient Air 

Quality Standards and relaxation of previously applicable 

requirements under the Clean Air Act. 

For the reasons stated below, we deny South Coast’s 

petition for review, and grant in part and deny in part that of 

the Environmental Petitioners. 

I. BACKGROUND

A. The Clean Air Act Framework

The Clean Air Act (“CAA” or “Act”) directs the EPA to 

set National Ambient Air Quality Standards (“NAAQS”) for 

air pollutants “allowing an adequate margin of safety . . . 

requisite to protect the public health.” 42 U.S.C. § 7409(b)(1). 

The CAA also requires the EPA to establish air quality control 

regions and designate them as “attainment” for “any area . . .

that meets” the NAAQS, “nonattainment” for “any area that 

does not meet” the NAAQS, and “unclassifiable” for “any area 
4

that cannot be classified on the basis of available information.” 

§ 7407(d)(1)(A). 

The EPA must classify each area “designated 

nonattainment for ozone” as “marginal,” “moderate,” 

“serious,” “severe,” or “extreme” based on the degree to which 

the ozone level in the area exceeds the NAAQS. § 7511. “An 

area that exceeds the NAAQS by a greater margin is given 

more time to meet the standard but is subjected to progressively 

more stringent emissions controls for ozone precursors, 

namely, volatile organic compounds (VOCs) and oxides of 

nitrogen (NOx).” Natural Res. Def. Council v. EPA (NRDC 

2009), 571 F.3d 1245, 1250 (D.C. Cir. 2009). 

The Act places on the states “the primary responsibility for 

assuring air quality” by submitting state implementation plans 

(“SIPs”) that specify how they will achieve and maintain 

compliance with the NAAQS. 42 U.S.C. § 7407(a). States 

must formally adopt SIPs through state notice and comment 

rulemaking and then submit the SIPs to the EPA for approval. 

§ 7410(a). For those areas designated as “nonattainment,” SIPs 

must show how the areas will achieve and maintain the relevant 

NAAQS. Id. 

A nonattainment area may be redesignated to attainment if 

the EPA (1) has determined that the area has attained the 

applicable NAAQS; (2) has fully approved the applicable SIP 

under § 7410(k); (3) has determined that the attainment is due 

to permanent and enforceable emissions reductions; (4) has 

fully approved a § 7505a “maintenance plan,” which 

demonstrates that the area will maintain the NAAQS for at least 

10 years after the redesignation, see § 7505a(a); and (5) has 

determined that the state containing the area seeking 

redesignation has met all applicable SIP requirements. 
5

§ 7407(d)(3)(E). Areas redesignated as attainment are referred 

to as “maintenance areas.”

B. SIPs for Nonattainment Areas

As is relevant to this case, the Clean Air Act requires SIPs 

for nonattainment areas to include the following provisions:

1. Reasonable Further Progress

SIPs for nonattainment areas “shall require reasonable 

further progress.” § 7502(c)(2). “Reasonable further progress”

is defined as “such annual incremental reductions in emissions 

of the relevant air pollutants as are required by this part or may 

reasonably be required by [the EPA] for the purpose of 

ensuring attainment of the applicable [NAAQS] by the 

applicable date.” § 7501(1). The Clean Air Act requires an 

area in a moderate or greater degree of nonattainment to reduce 

emissions of VOCs by fifteen percent in the first six years after 

November 15, 1990. § 7511a(b)(1)(A). For areas in a serious 

or greater degree of nonattainment, subsequent reductions in 

VOC emissions must average three percent per year over each 

consecutive three-year period until the area reaches attainment. 

§ 7511a(c)(2)(B). 

2. Reasonably Available Control 

Technology

SIPs for ozone nonattainment areas must also “provide for 

the implementation of all reasonably available control 

measures as expeditiously as practicable (including such 

reductions in emissions from existing sources in the area as 

may be obtained through the adoption, at a minimum, of 

reasonably available control technology).” § 7502(c)(1). For 

nonattainment areas classified as moderate and above, SIPs 
6

must “require the implementation of reasonably available 

control technology” with respect to all major sources of VOCs

in the area and any sources that emit VOCs in the area that are 

covered by a control technique guideline. § 7511a(b)(2). The 

reasonably available control technology requirement also 

applies to major sources of NOx. § 7511a(f). 

3. New Source Review

SIPs governing nonattainment areas must require permits 

for the construction of new or modified sources of air pollution. 

§§ 7502(c)(5), 7503, 7410(a)(2)(C). The goal of New Source 

Review is to require permits to ensure that new or modified 

sources will not exacerbate the pollution problem in the 

nonattainment area. § 7503(a)(1)(A), (a)(2), (c). New Source

permits for major sources of VOCs require the proposed source 

(1) to comply with the lowest achievable emissions rate and 

(2) to obtain pollution offsets representing equal or greater 

reductions of a pollutant at issue in the area. Id. 

4. Conformity

The Act mandates that nonattainment and maintenance 

areas are subject to “conformity requirements,” so that “[n]o 

department, agency, or instrumentality of the Federal

Government shall engage in, support in any way or provide 

financial assistance for, license or permit, or approve, any 

activity which does not conform to an implementation plan.” 

§ 7506(c)(1), (5). Federally funded projects must “conform” 

to SIPs, meaning that the projects will not “cause or contribute 

to any new violation,” “increase the frequency or severity of 

any existing violation,” or “delay timely attainment of any 

standard or any required interim emission reductions or other 

milestones in any area.” § 7506(c)(1)(B). These areas are also 

subject to the more specific transportation conformity
7

requirements, whereby federal agencies may not “approve, 

accept or fund any transportation plan, program or project 

unless” it conforms to an applicable SIP. § 7506(c)(2). With 

respect to transportation conformity requirements, the EPA is 

responsible for promulgating, and periodically updating, 

“criteria and procedures for demonstrating and assuring 

conformity in the case of transportation plans, programs, and 

projects.” § 7506(c)(4)(B). 

5. Contingency Measures

SIPs must include contingency measures that take effect 

automatically “if the area fails to make reasonable further 

progress, or to attain the [NAAQS] by the attainment date.” 

§§ 7502(c)(9), 7511a(c)(9).

C. Anti-Backsliding Measures for Revoked NAAQS

The Clean Air Act requires the EPA to “complete a 

thorough review” of each NAAQS every five years and “make 

such revisions . . . and promulgate such new standards as may 

be appropriate.” § 7409(d)(1). In promulgating new standards, 

if the EPA relaxes a NAAQS, it shall promulgate antibacksliding measures for all areas that have not attained that 

standard as of the date of the relaxation. § 7502(e). The antibacksliding measures “shall provide for controls which are not 

less stringent than the controls applicable to areas designated 

nonattainment before such relaxation.” Id. 

D. Ozone NAAQS

In 1979, the EPA promulgated the first ozone NAAQS 

based on a one-hour average concentration of 0.12 parts per 

million (ppm). Revisions to the NAAQS for Photochemical 

Oxidants, 44 Fed. Reg. 8202, 8202 (Feb. 8, 1979). In 1997, 
8

after determining that the one-hour NAAQS was inadequate to 

protect public health, the EPA promulgated a new NAAQS 

based on an eight-hour average of 0.08 ppm. NAAQS for 

Ozone, 62 Fed. Reg. 38,856, 38,858 (July 18, 1997). Although 

the EPA replaced the one-hour NAAQS with an eight-hour 

NAAQS, it determined that it would continue to enforce the 

one-hour NAAQS until “an area has attained air quality that 

meets the 1-hour standard.” Implementation of Revised Air 

Quality Standards for Ozone and Particulate Matter, 62 Fed. 

Reg. 38,421, 38,424 (July 18, 1997). In a 2004 rule, the EPA 

revoked the one-hour NAAQS effective June 15, 2005. Final 

Rule to Implement the 8-Hour Ozone NAAQS—Phase 1, 69 

Fed. Reg. 23,951, 23,951 (Apr. 30, 2004). This Court held that 

the EPA has the “authority to revoke the one-hour standard so 

long as adequate anti-backsliding provisions are introduced.” 

South Coast Air Quality Mgmt. Dist. v. EPA, 472 F.3d 882, 899 

(D.C. Cir. 2006), clarified on denial of reh’g, 489 F.3d 1245 

(D.C. Cir. 2007). 

In 2008, the EPA determined that the 1997 NAAQS was 

inadequate to protect public health. The EPA therefore 

promulgated a new NAAQS of 0.075 ppm of ozone averaged 

over eight hours. NAAQS for Ozone, 73 Fed. Reg. 16,436, 

16,436 (Mar. 27, 2008). “The 2008 ozone NAAQS retains the 

same general form and averaging time as the 0.08 ppm 

NAAQS set in 1997, but is set at a more stringent level.” 

Implementation of the 2008 NAAQS for Ozone: State 

Implementation Plan Requirements, 80 Fed. Reg. 12,264, 

12,265 (Mar. 6, 2015). 

E. The Final Rule

On March 6, 2015, the EPA finalized a rule that “revises 

existing regulations and guidance as appropriate to aid in the 

implementation of the 2008 ozone NAAQS.” 80 Fed. Reg. at 
9

12,265. As part of the Final Rule, the EPA revoked the 1997 

NAAQS “for all purposes and establish[ed] anti-backsliding 

requirements for areas that remain designated nonattainment 

for the revoked NAAQS.” Id. 

II. STANDARD OF REVIEW

We will not set aside EPA action under the Clean Air Act 

unless we determine that such action is “arbitrary, capricious, 

an abuse of discretion, or otherwise not in accordance with 

law.” 42 U.S.C. § 7607(d)(9)(A). The EPA’s interpretation of 

the Clean Air Act is reviewed under the familiar two-step 

framework of Chevron U.S.A., Inc. v. Natural Resources 

Defense Council, Inc., 467 U.S. 837 (1984), whereby we first 

look to the statute’s language to determine if Congress has 

“directly spoken to the precise question at issue.” Id. at 842. 

If Congress has directly spoken to the precise question, then we 

must “give effect to the unambiguously expressed intent of 

Congress.” Id. at 843. If, however, “the statute is silent or 

ambiguous with respect to the specific issue,” we defer to the 

EPA’s interpretation of the Act so long as it “is based on a 

permissible construction of the statute.” Id.

Under those standards, we review in turn the crosspetitions of South Coast and the Environmental Petitioners.

III. SOUTH COAST’S PETITION

We begin with the simpler of the two petitions, that of 

South Coast. South Coast petitions this Court to invalidate the 

EPA’s interpretation of the CAA in the Final Rule that “states 

may not take credit for VOC or NOx reductions occurring from 

sources outside the nonattainment area for purposes of meeting 

the 15 percent [rate-of-progress] and 3 percent [reasonable 

further progress] requirements.” 80 Fed. Reg. at 12,273. South 
10

Coast argues that the EPA was not required to interpret “in the 

area” in the context of the reasonable further progress 

requirement to mean “in the nonattainment area.” See 42 

U.S.C. § 7511a(b)(1)(B). In promulgating the Final Rule, the 

EPA explained that in light of this Court’s decision in NRDC 

2009, 571 F.3d at 1256, “there is no legal basis” for “allowing 

states to credit reductions achieved at sources outside the 

nonattainment area.” 80 Fed. Reg. at 12,273. South Coast 

counters that our decision in NRDC 2009 does not mandate the 

EPA’s interpretation. Instead, South Coast contends that 

because downwind nonattainment areas are impacted by 

emissions from upwind areas, the EPA could reasonably 

interpret “in the area” in the context of the reasonable further 

progress requirement to mean the “transport couple area”—“a 

larger area consisting of the nonattainment area in question 

plus the upwind area from which emission reductions would be 

obtained.” 

The text here is unambiguous. The Clean Air Act requires 

nonattainment areas that are classified as moderate or above to 

plan for “reasonable further progress” measured from “baseline 

emissions,” which are defined as “the total amount of actual 

VOC or NOx emissions from all anthropogenic sources in the 

area during the” baseline year. 42 U.S.C. § 7511a(b)(1)(A), 

(b)(1)(B), (c)(2)(B), (d), (e). These statutory provisions refer 

to only one area, “the area.” Further, the term appears in a 

section entitled “Moderate Areas,” not a greater area. 

§ 7511a(b); see also § 7511(c)(1). 

South Coast contends that limiting the phrase “in the area” 

to nonattainment areas would produce absurd results. 

According to South Coast, it may be impossible for certain 

areas to achieve the necessary emissions reductions. Where the 

purpose of the Clean Air Act is served by interpreting “in the 
11

area” to mean “transport couple area,” South Coast argues that 

the statutory language is ambiguous. 

However, the Clean Air Act provides for an alternative to 

reducing emissions of pollutants by fixed percentages. 

§ 7511a(b)(1)(A)(ii), (c)(2)(B). Nonattainment areas may 

reduce emissions by less than 15 percent if they (1) implement 

controls on a broader range of new and existing stationary 

sources and (2) include in their SIP “all measures that can 

feasibly be implemented in the area, in light of technological 

achievability” and “measures that are achieved in practice by 

sources in the same source category in nonattainment areas of 

the next higher category.” § 7511a(b)(1)(A)(ii). Likewise, 

nonattainment areas may reduce emissions by less than three 

percent if the SIP “includes all measures that can feasibly be 

implemented in the area, in light of technological 

achievability” and “measures that are achieved in practice by 

sources in the same source category in nonattainment areas of 

the next higher classification.” § 7511a(c)(2)(B)(ii). 

Moreover, states may also ask the EPA to approve new 

boundaries for air quality control regions. See 42 U.S.C. 

§ 7407(b)-(c). In light of the alternatives provided for in the 

Clean Air Act, South Coast has failed to meet the 

“exceptionally high burden” required to demonstrate absurdity. 

Friends of Earth, Inc. v. EPA, 446 F.3d 140, 146 (D.C. Cir. 

2006). 

In sum, considering the grammar and context of 

§ 7511a(b)(1)(B), we hold at Chevron step one that “in the 

area” unambiguously refers to baseline emissions within the 

nonattainment area. Accordingly, we deny South Coast’s 

petition. 
12

IV. ENVIRONMENTAL PETITIONERS’ 

PETITION 

Environmental Petitioners petition this Court to vacate 

several parts of the Final Rule. We take each challenge in turn. 

A. Waiver of Statutory Attainment Deadlines 

Associated with the 1997 NAAQS

Environmental Petitioners seek to invalidate the Final 

Rule’s revocation of the 1997 NAAQS. 80 Fed. Reg. at 12,296. 

They argue that by revoking the 1997 NAAQS, the Final Rule 

arbitrarily waives the obligation to attain the 1997 NAAQS by 

the statutory deadline. The EPA counters that the Clean Air 

Act authorizes revocation of a superseded NAAQS so long as 

adequate anti-backsliding measures are in place. 

We have already held that the EPA may revoke a previous 

NAAQS in full “so long as adequate anti-backsliding 

provisions are introduced.” South Coast, 472 F.3d at 899. But 

in the Final Rule, the EPA failed to introduce adequate antibacksliding provisions. 

Pursuant to the Clean Air Act, anti-backsliding provisions

“shall provide for controls which are not less stringent than the 

controls applicable to areas designated nonattainment before 

such relaxation.” 42 U.S.C. § 7502(e). Penalties for not 

meeting attainment deadlines such as fees and activation of 

contingency measures are unambiguously “controls” because 

they are “designed to constrain ozone pollution.” South Coast, 

472 F.3d at 902-03. Likewise, reclassification is also a control 

because it is “designed to constrain ozone pollution.” See id. 

Areas that fail to timely attain are required to reclassify and be 

subject to more stringent emissions controls. 42 U.S.C. 

§§ 7511(b)(2), 7511a(i). If the EPA were allowed to remove 
13

the deadlines that trigger those penalties, “a state could go 

unpenalized without ever attaining” the NAAQS. South Coast, 

472 F.3d at 902-03. 

The Final Rule provides that “the EPA is required to 

determine whether an area attained the 1-hour or 1997 ozone 

NAAQS by the area’s attainment date solely for antibacksliding purposes to address an applicable requirement for 

nonattainment contingency measures and CAA section 185 fee 

programs.” 80 Fed. Reg. at 12,315. But the Final Rule 

specifically waives the obligation “to reclassify an area to a 

higher classification for the 1997 ozone NAAQS” based on a 

failure to meet the 1997 NAAQS attainment deadlines. Id. As 

a result, the Final Rule allows areas that fail to timely attain to 

avoid being subject to more stringent emissions controls. 

Therefore, the Final Rule relaxed the controls applicable to 

areas designated nonattainment under the 1997 NAAQS in 

contravention of the anti-backsliding requirement. 

Accordingly, we grant this part of Environmental Petitioners’ 

petition and vacate the Final Rule as to the waived statutory 

attainment deadlines associated with the 1997 NAAQS.

B. Removal of Anti-Backsliding Requirements

for Areas Designated Nonattainment Under 

the 1997 NAAQS

Environmental Petitioners also seek to invalidate other

provisions of the Final Rule that they allege contravene the 

Clean Air Act’s anti-backsliding requirements. The Final Rule 

provides for three procedures by which areas designated 

nonattainment under the 1997 NAAQS may remove certain 

anti-backsliding requirements and shift other requirements

from the active portion of their SIPs to the contingency 

measures portion. 80 Fed. Reg. at 12,299-12,304. 
14

1. Orphan Nonattainment Areas

The first procedure applies to areas designated attainment 

for the 2008 NAAQS, but nonattainment for the 1997 NAAQS. 

Id. at 12,301-12,302. Environmental Petitioners refer to these 

areas as “orphan nonattainment areas.” For orphan 

nonattainment areas, “states are not required to adopt any 

outstanding applicable requirements for the revoked 1997 

standard.” Id. at 12,302. Under the Final Rule, orphan 

nonattainment areas “are not subject to transportation or 

general conformity requirements.” Id. at 12,300. In addition, 

orphan nonattainment areas are no longer required to retain 

New Source Review programs in their SIPs. Id. at 12,299. 

Instead, these areas are subject to Prevention of Significant 

Deterioration (“PSD”) requirements. Id. States may also 

request that other anti-backsliding requirements be shifted to 

their list of contingency measures based on initial 2008 

designations. Id. at 12,314. Finally, the Final Rule does not

require orphan nonattainment areas to submit maintenance 

plans under § 7505a, and deems the requirement for 

maintenance under § 7410(a)(1) to be satisfied by the area’s 

approved Prevention of Significant Deterioration SIP. Id. at 

12,302, 12,314. 

(a) Environmental Petitioners argue that elimination of 

New Source Review and conformity in orphan nonattainment 

areas violates the anti-backsliding requirements. The EPA 

argues that the Final Rule lawfully lifts the requirement for 

New Source Review and conformity for orphan nonattainment 

areas because the 2008 NAAQS is more stringent than the 1997 

NAAQS. According to the EPA, areas that have attained the 

2008 NAAQS have necessarily attained the 1997 NAAQS. 

This Court previously held that New Source Review is

unambiguously a “control” under § 7502(e). South Coast, 472 
15

F.3d at 901-02. Environmental Petitioners also contend that 

conformity is a “control” under § 7502(e). The EPA does not 

address general conformity requirements, but argues that our 

decision in South Coast does not require transportation 

conformity as an anti-backsliding control. According to the

EPA, in South Coast we held that only existing motor vehicle 

emissions budgets are required anti-backsliding controls, not 

the conformity requirement itself. 

The Final Rule provides that 1997 nonattainment areas are 

“no longer . . . required to demonstrate transportation 

conformity for the 1997” NAAQS after the 1997 NAAQS is 

revoked. 80 Fed. Reg. at 12,284. Pursuant to the Final Rule,

“the latest approved or adequate emission budgets for a 

previous ozone NAAQS . . . would continue to be used in 

conformity determinations for the 2008 ozone NAAQS until 

emission budgets are established and found adequate or are 

approved for the 2008 ozone NAAQS.” Id. But the Final Rule 

provides that areas “designated attainment for the 2008 ozone 

NAAQS are not subject to transportation or general conformity 

requirements regardless of their designation for the 1997 ozone 

NAAQS at the time of revocation of that NAAQS.” Id. at 

12,300. 

The EPA is correct that South Coast held only that “onehour conformity emissions budgets constitute ‘controls’ under 

section 172(e).” 472 F.3d at 904. Furthermore, on rehearing, 

we clarified that our decision with respect to conformity 

determinations “speaks only to the use of one-hour motor 

vehicle emissions budgets as part of eight-hour conformity 

determinations until eight-hour motor vehicle emissions 

budgets are available.” South Coast Air Quality Mgmt. Dist. v. 

EPA, 489 F.3d 1245, 1248 (D.C. Cir. 2007). But our decision 

that emissions budgets constitute controls does not preclude 

that “conformity” requirements in general are controls. 
16

Conformity requirements are designed to constrain ozone 

pollution as they have the “purpose of eliminating or reducing 

the severity and number of violations of the [NAAQS] and 

achieving expeditious attainment of such standards.” 42 

U.S.C. § 7506(c)(1)(A). Therefore, conformity requirements

also are unambiguously “controls” under § 7502(e). 

Although orphan nonattainment areas were originally 

designated attainment under the 2008 NAAQS, they have 

never been redesignated to attainment pursuant to 

§ 7407(d)(3)(E) under the 1997 NAAQS. The EPA may not 

permit termination of New Source Review and conformity in 

the absence of formal redesignation under § 7407(d)(3)(E). 

See Natural Res. Def. Council v. EPA, 643 F.3d 311, 322-23

(D.C. Cir. 2011) (rejecting final rule that allowed attainment of 

the 1997 NAAQS to permit termination of the fees control for 

the one-hour NAAQS). As we stated in our prior South Coast

opinion, “EPA is required by statute to keep in place measures 

intended to constrain ozone levels—even the ones that apply to 

outdated standards—in order to prevent backsliding.” South 

Coast, 472 F.3d at 905. Accordingly, we grant Environmental 

Petitioners’ petition and vacate the Final Rule as to the removal 

of New Source Review and conformity controls from orphan 

nonattainment areas. 

(b) Environmental Petitioners argue that permitting states 

to shift other anti-backsliding requirements to contingency 

measures violates the Clean Air Act. The EPA responds that 

states must continue implementing all such measures in 

previously approved SIPs unless the EPA approves requests to 

amend SIPs to convert such requirements into contingency 

measures. For the same reasons that the EPA may not permit 

states to eliminate New Source Review and transportation 

conformity, the EPA also may not permit states to shift other 

anti-backsliding requirements to their list of contingency 
17

measures without complying with the statutory requirements 

for redesignation. Therefore, we grant Environmental 

Petitioners’ petition and vacate the Final Rule as to permitting 

states to move anti-backsliding requirements for orphan 

nonattainment areas to their list of contingency measures based 

on initial 2008 designations. 

(c) Likewise, without requiring nonattainment areas to 

meet the requirements for reattainment under § 7407(d)(3)(E), 

the EPA improperly waived the requirement that states adopt 

outstanding applicable requirements for the revoked 1997 

NAAQS. Therefore, we grant Environmental Petitioners’ 

petition and vacate the Final Rule as to waiving the requirement

that states adopt outstanding applicable requirements for the 

revoked 1997 NAAQS. 

(d) Environmental Petitioners argue that the Final Rule 

impermissibly waives the maintenance requirements under 

§ 7410(a)(1) for orphan nonattainment areas. The Final Rule 

allows approved Prevention of Significant Deterioration SIPs 

to satisfy the obligation to submit a maintenance plan under 

§ 7410(a)(1). 80 Fed. Reg. at 12,302. Prevention of 

Significant Deterioration SIPs bar the construction of major 

sources of emissions without compliance with certain statutory 

requirements. See § 7475(a).

 

The Final Rule also does not require orphan nonattainment 

areas to submit a maintenance plan under § 7505a. 80 Fed. 

Reg. at 12,302. The EPA contends that there is no statutory 

requirement for a separate maintenance plan for orphan 

nonattainment areas. However, one of the five requirements 

for redesignation under § 7407(d)(3)(E) is that the EPA 

“approve[] a maintenance plan for the area as meeting the 

requirements of section 7505a of this title.” 

§ 7407(d)(3)(E)(iv). Therefore, the Final Rule is inconsistent 
18

with the clear text of § 7407(d)(3)(E) in waiving the § 7505a(a) 

maintenance plan requirement for orphan nonattainment areas.

Environmental Petitioners also appear to contend that even 

with a § 7505a maintenance plan, the Final Rule would violate 

the maintenance requirement under § 7410(a)(1) because 

§ 7410(a)(1) requires something more than a Prevention of 

Significant Deterioration SIP and a § 7505a maintenance plan. 

Specifically, Environmental Petitioners argue that a SIP for an 

orphan nonattainment area must include a plan to ensure that 

pollution from existing sources and new sources not subject to 

the PSD requirements does not cause those areas to fall into 

violation of the 2008 NAAQS. According to Environmental 

Petitioners, without such safeguards, existing measures have 

proved insufficient to provide for continuing attainment of the 

2008 NAAQS. 

Section 7410(a)(1) provides that SIPs must provide for 

“implementation, maintenance, and enforcement” of the 

NAAQS. The statute clearly requires “maintenance” 

provisions to be included in SIPs, but the statute does not 

require a separate SIP component entitled “maintenance plan.” 

In fact, the statute provides no guidance for what SIPs must 

include in order to comply with the § 7410(a)(1) maintenance 

requirement beyond the criteria laid out in § 7410(a)(2). 

Environmental Petitioners do not allege the agency has 

eliminated § 7410(a)(2)’s requirements. Therefore, the Final 

Rule will be upheld so long as it is neither unreasonable nor 

arbitrary. 

The EPA justified the rule by explaining that a § 7471

“PSD SIP, in conjunction with the other already-existing 

statutory and regulatory provisions . . . are generally sufficient 

to prevent backsliding, and to satisfy the requirement for 

maintenance under” § 7410(a)(1). 80 Fed. Reg. at 12,302. 
19

According to the EPA, the “control measures implemented by 

these areas and included in their SIPs have already produced 

sufficient emissions reductions to achieve air quality that 

attained the 1997 ozone NAAQS, and resulted in an attainment 

designation for the more stringent 2008 ozone NAAQS.” Id.

The EPA therefore concluded that “the burden of developing 

an approvable [§ 7410(a)(1)] maintenance plan for the 2008 

ozone NAAQS would outweigh any compensating benefit for 

an area that is already attaining that NAAQS and that is subject 

to prior nonattainment requirements which are already 

incorporated into the SIP and have been sufficient to bring the 

area into attainment of both the 1997 and 2008 standards.” Id. 

The EPA adequately explained why measures that 

achieved attainment of both the 1997 NAAQS and the 2008 

NAAQS should be adequate to maintain the same 2008 

NAAQS that has already been attained. The EPA also 

thoughtfully responded to comments that suggested the 

measures on which the EPA relies are insufficient to satisfy the 

§ 7410(a)(1) maintenance requirement. Under these 

circumstances, the EPA’s determination is neither 

unreasonable nor arbitrary. 

Environmental Petitioners contend that the EPA has not 

addressed comments that identified examples of orphan 

nonattainment areas that purportedly were in fact not attaining 

the 2008 NAAQS. These comments were not raised in regard 

to the § 7410(a)(1) maintenance requirement. Instead, they 

appear to have been raised in response to other alleged 

shortcomings with the proposed rule. Moreover, the EPA 

appears to have addressed those arguments in its response to 

comments. Response to Comments on Implementation of the 

2008 NAAQS for Ozone: SIP Requirements (Feb. 13, 2015) at 

133. In any event, the comments are directed toward

enforcement issues with the current NAAQS, not issues with
20

the underlying rule. Accordingly, the EPA’s decision not to

implement a separate § 7410(a) maintenance plan is neither 

arbitrary nor unreasonable. 

Therefore, we grant Environmental Petitioners’ petition

and vacate the Final Rule with respect to the EPA’s waiving of 

the § 7505a(a) maintenance plan requirement for orphan 

nonattainment areas, and we deny Environmental Petitioners’

petition with respect to the § 7410(a)(1) maintenance 

requirement’s application to orphan nonattainment areas in 

other respects. 

2. Formal Redesignation 

The second procedure by which areas designated 

nonattainment under the 1997 NAAQS may remove certain 

anti-backsliding requirements and shift other requirements 

from the active part of their SIPs to the contingency measures 

part involves areas designated nonattainment under both the 

2008 NAAQS and the 1997 NAAQS. 80 Fed. Reg. at 12,303-

04. The Final Rule allows states to seek formal redesignation 

to attainment based on the 2008 NAAQS with an approved 

maintenance plan that addresses the current and revoked 

NAAQS. Id. at 12,304. Under this procedure, states may 

terminate and remove any applicable anti-backsliding 

requirements, including New Source Review requirements,

from the active part of their SIPs. Id. 

The EPA properly subjected these areas to antibacksliding requirements when the 1997 NAAQS was revoked 

because they were still in nonattainment at the time of 

revocation. See § 7502(e). The Act is ambiguous as to whether 

such areas must retain these anti-backsliding requirements after 

they are successfully redesignated as attainment areas under the 

2008 NAAQS. Unlike orphan nonattainment areas, these areas 
21

have met the statutory requirements for redesignation under 

§ 7407(d)(3)(E). Therefore, these areas have shown, for 

example, that “the[ir] improvement in air quality is due to 

permanent and enforceable reductions in emissions resulting 

from implementation of the applicable implementation plan.” 

§ 7407(d)(3)(E)(iii). Although these areas may not have been 

redesignated with respect to the 1997 NAAQS, by meeting the 

statutory requirements for redesignation with respect to the 

2008 NAAQS, they necessarily also meet the less restrictive 

requirements for redesignation under the 1997 NAAQS. 

Accordingly, it is reasonable for these areas to shed their antibacksliding controls by virtue of meeting the five statutory 

criteria for redesignation. Therefore, we deny Environmental 

Petitioners’ petition with respect to this aspect of the Final 

Rule. 

3. Redesignation Substitute

The third procedure by which areas designated 

nonattainment under the 1997 NAAQS may remove certain 

anti-backsliding requirements and shift other requirements 

from the active part of their SIPs to the contingency measures 

part also involves areas designated nonattainment under both 

the 2008 NAAQS and the 1997 NAAQS. This procedure 

allows states “to submit a redesignation substitute request for a 

revoked NAAQS.” 80 Fed. Reg. at 12,304. The redesignation

substitute request “is based on” the Clean Air Act’s “criteria 

for redesignation to attainment” under § 7407(d)(3)(E), 80 Fed. 

Reg. at 12,305, but it does not require full compliance with all 

five conditions in § 7407(d)(3)(E). The Clean Air Act 

unambiguously requires nonattainment areas to satisfy all five 

of the conditions under § 7407(d)(3)(E) before they may shed 

controls associated with their nonattainment designation. The 

redesignation substitute lacks the following requirements of 

§ 7407(d)(3)(E): (1) the EPA has “fully approved” the 
22

§ 7410(k) implementation plan; (2) the area’s maintenance 

plan satisfies all the requirements under § 7505a; and (3) the 

state has met all relevant § 7410 requirements. 80 Fed. Reg. at 

12,305. Because the “redesignation substitute” does not 

include all five statutory requirements, it violates the Clean Air 

Act. Therefore, we grant Environmental Petitioners’ petition 

and vacate the Final Rule as to the “redesignation substitute.” 

C. Baseline Year

The Clean Air Act measures Reasonable Further Progress

by using a baseline year as the starting point. Nonattainment 

areas must reduce emissions of pollutants by fixed percentages 

compared to the pollutant level in a baseline year. 42 U.S.C. 

§ 7511a(b)(1)(A), (B). The initial baseline year under the 

statute is 1990, id., but the statute does not define baseline years

for future NAAQS. In the Final Rule, the EPA defined the 

baseline year as 2011, which is the “calendar year for the most 

recently available triennial emission inventory at the time [rateof-progress/reasonable further progress] plans are developed.” 

80 Fed. Reg. at 12,272. The Final Rule also allows states to 

select an alternative baseline year between 2008 and 2012 if 

they provide appropriate justification. Id.

Environmental Petitioners argue that this rule is unlawful 

because the Clean Air Act requires the baseline year to be the 

year of designation/classification, which in the case of the 2008 

NAAQS is 2012. While an initial baseline year of 1990 is 

specified by statute, the Clean Air Act is silent regarding future 

baseline years. Therefore, this question is governed by 

Chevron step two. The Reasonable Further Progress 

requirement ensures that states make regular emissions

reductions to achieve timely attainment. See § 7511a. To

monitor their progress in achieving regular emissions

reductions, states are required to prepare an emissions
23

inventory every three years. § 7511a(a)(3)(A). The EPA’s 

selection of 2011 as the baseline year is reasonable because it 

is tied to the three-year statutory cycle for emissions 

inventories. Id. Therefore, we deny Environmental 

Petitioners’ challenge to the setting of 2011 as the baseline 

year. 

With respect to selection of an alternative baseline year 

between 2008 and 2012, the EPA has failed to provide a 

statutory justification. The “EPA must ‘ground its reasons for 

action or inaction in the statute,’ rather than on ‘reasoning 

divorced from the statutory text.’” Natural Res. Def. Council

v. EPA (NRDC 2014), 777 F.3d 456, 468 (D.C. Cir. 2014) 

(quoting Utility Air Regulatory Grp. v. EPA, 134 S. Ct. 2427, 

2441 (2014)). The EPA based its creation of the alternative 

baseline year option on the convenience of allowing 

nonattainment areas to receive credit for emissions reduction 

measures adopted prior to the baseline year. Because the EPA 

has no statutory basis for the alternative baseline year

provision, we grant Environmental Petitioners’ petition and 

vacate the Final Rule as to the alternative baseline year option. 

D. Fifteen-Percent Rule

The Clean Air Act requires an area in a moderate or greater 

degree of nonattainment to reduce emissions of VOCs by 

fifteen percent within six years of the baseline year. 42 U.S.C. 

§ 7511a(b)(1)(A). The Final Rule interprets this requirement 

as meaning that “an area that has already met the 15 percent 

requirement for VOC under either the 1-hour ozone NAAQS 

or the 1997 ozone NAAQS (for the first 6 years after the 

[reasonable further progress] baseline year for the prior ozone 

NAAQS) would not have to fulfill that requirement again.” 80 

Fed. Reg. at 12,271; see also id. at 12,276. The Environmental 

Petitioners argue that the rule is unlawful because the 
24

interpretation allows areas to avoid actually achieving 

emissions reductions to satisfy the fifteen-percent requirement. 

The Final Rule does not require nonattainment areas that 

have previously revised their SIPs to address the Clean Air 

Act’s fifteen-percent requirement to revise their SIPs again. If 

an area fails to achieve this reduction according to their plan, a 

petitioner may file for injunctive relief or the EPA may pursue 

an enforcement action. Environmental Petitioners argue that 

the Final Rule allows nonattainment areas to omit the fifteenpercent requirement even if they never previously achieved a 

fifteen-percent reduction. The EPA has represented that the 

provision at issue in this case is the same as that at issue in 

NRDC 2009, 571 F.3d 1245. In NRDC 2009, the EPA rule 

allowed areas that had revised their SIPs to include a fifteenpercent VOC emissions reduction to not be subjected to a 

second fifteen-percent requirement under the new NAAQS. Id.

at 1261. We held that “the EPA reasonably resolved a statutory 

ambiguity under step 2 of the framework set out in Chevron.” 

Id. at 1262. We accept the EPA’s representation that the 

fifteen-percent requirement in the Final Rule is the same as the 

provision at issue in NRDC 2009. Therefore, because the 

EPA’s interpretation is permissible, we deny Environmental

Petitioners’ challenge to the fifteen-percent reduction plan 

waiver. 

E. Area-Wide Emissions Reductions

The Clean Air Act requires nonattainment areas to achieve 

“such reductions in emissions from existing sources in the 

area” as can be achieved by the adoption of Reasonably 

Available Control Technology (“RACT”). 42 U.S.C. 

§ 7502(c)(1). The Final Rule allows nonattainment areas to 

satisfy the NOx RACT requirement by using averaged areawide emissions reductions. 80 Fed. Reg. at 12,278-79. Thus,
25

“states may demonstrate as part of their NOx RACT SIP 

submittal that the weighted average NOx emission rate from all 

sources in the nonattainment area subject to RACT meets NOx

RACT requirements.” Id. at 12,278. Environmental 

Petitioners argue that this rule violates the clear terms of the 

Clean Air Act, which require each individual source to meet 

the NOx RACT requirement. 

They contend that § 7511a(b)(2) requires implementation 

of RACT with respect to “all” major sources, and “all” means 

“each one of.” Section 7511a(b)(2) requires states to submit 

revisions to SIPs “to include provisions to require the 

implementation of reasonably available control technology 

under section 7502(c)(1) of this title with respect to each of” 

three specific categories of VOC sources, including “all . . . 

major stationary sources of VOCs that are located in the area.” 

Pursuant to § 7511a(f), that plan provision applies to “major 

stationary sources” of NOx. Section 7511a(b)(2) refers to “all” 

“major stationary sources” and requires implementation of 

RACT “with respect to” that entire category of sources. The 

statute does not specify that “each one of” the individual 

sources within the category of “all” “major sources” must 

implement RACT. Environmental Petitioners argue that the 

only reasonable dictionary definition of “all” when used with a 

plural noun (major stationary sources) is “each one of.” 

Instead, when used to refer to a plural noun, the word “all” may 

express an aggregate and be defined as the “whole number or 

sum of.” Black’s Law Dictionary 74 (6th ed. 1990). This 

definition is consistent with the categorical approach taken by 

the EPA. In short, the plain language—in the context of the 

interrelationship between §§ 7511a(b)(2) and 7502(c)(1)—

does not mandate RACT for each individual source. 

Therefore, as discussed above, we cannot strike down the 

EPA’s reasoned interpretation of the ambiguous term at 
26

Chevron step one, see Section II, supra. We must instead 

uphold the EPA’s interpretation, provided it is reasonable, 

under Chevron step two. See Chevron, 467 U.S. at 842-43.

We further note that § 7511a(b)(2) refers to § 7502(c)(1), 

which provides that SIP “provisions shall provide for the 

implementation of all reasonably available control measures as 

expeditiously as practicable (including such reductions in 

emissions from existing sources in the area as may be obtained 

through the adoption, at a minimum, of reasonably available 

control technology).” § 7502(c)(1). Section 7502(c)(1) does 

not require reductions from each individual major source. 

Instead, it requires “reductions in emissions from existing 

sources in the area,” and other than mandating that 

implementation be as “expeditious[] as practicable,” the 

section is ambiguous as to how areas are required to achieve 

those reductions. 

The EPA’s interpretation reasonably allows nonattainment 

areas to meet RACT-level emissions requirements through 

averaging within a nonattainment area. Therefore, we deny

Environmental Petitioners’ petition as to the EPA’s 

construction of the RACT requirement. 

F. Waiving Requirements for Areas Designated 

Maintenance Under the 1997 NAAQS

Environmental Petitioners seek to have us invalidate 

several provisions of the Final Rule that apply to areas

designated attainment for the 2008 NAAQS after being 

designated maintenance areas under the 1997 NAAQS 

(“orphan maintenance areas”). 
27

1. Elimination of Transportation 

Conformity

As with orphan nonattainment areas, the Final Rule 

declares that orphan maintenance areas are “no longer . . .

required to demonstrate transportation conformity for the 1997 

ozone NAAQS after the 1997 ozone NAAQS is revoked.” 80 

Fed. Reg. at 12,284. Environmental Petitioners argue that the 

elimination of transportation conformity in orphan 

maintenance areas violates the Clean Air Act. Section 

7506(c)(5) provides that conformity requirements apply to 

“(A) a nonattainment area and each pollutant for which the area 

is designated as a nonattainment area; and (B) an area that was 

designated as a nonattainment area but that was later 

redesignated . . . as an attainment area and that is required to 

develop a maintenance plan under section 7505a.” 

We previously explained that the EPA lacks the authority 

to revoke transportation conformity for orphan nonattainment 

areas. See Section IV.B.1(a), supra. The EPA argues that it 

is permitted to remove conformity requirements for orphan 

maintenance areas because such areas became attainment areas 

for the 1997 NAAQS prior to the date on which it was revoked. 

As a result, the EPA argues that these areas are not subject to 

anti-backsliding requirements, so there is no statutory 

requirement that they maintain the transportation conformity 

requirement. We disagree. 

In contrast to nonattainment areas, which § 7506(c)(5) 

references by their status as “nonattainment area[s],” 

maintenance areas are referenced by previous events: “an area 

that was designated as a nonattainment area but that was later 

redesignated . . . as an attainment area and that is required to 

develop a maintenance plan under section 7505a.” 

§ 7506(c)(5) (emphases added). Although the Final Rule 
28

revoked the 1997 NAAQS, it cannot revoke the statutory status 

of orphan maintenance areas. Even after revocation of the 

1997 NAAQS, an orphan maintenance area is “an area that was

designated as a nonattainment area but that was later 

redesignated . . . as an attainment area.” 

It is irrelevant that this previous designation and 

redesignation occurred before the prior NAAQS was revoked 

because nothing in the Clean Air Act allows the EPA to waive 

this unambiguous statutory requirement. Moreover, the Act 

clearly contemplates new NAAQS being promulgated within 

ten years of an area’s redesignation to attainment because the 

statute requires the EPA to review NAAQS every five years 

and to “promulgate such new standards as may be appropriate.” 

§ 7409(d)(1). Therefore, the revocation of the 1997 NAAQS 

does not waive the unambiguous mandate that conformity 

requirements apply to orphan maintenance areas. Accordingly, 

we grant Environmental Petitioners’ petition as to the 

elimination of transportation conformity in orphan 

maintenance areas. 

2. Section 7410(a)(1) Maintenance Planning 

Requirement

Environmental Petitioners contend that the Final Rule 

unlawfully waives the § 7410(a)(1) maintenance planning 

requirement for the 2008 NAAQS. 80 Fed. Reg. at 12,301. 

The Final Rule provides that an orphan maintenance area’s 

§ 7505a(a) maintenance plan for the revoked 1997 NAAQS 

and the state’s approved Prevention of Significant

Deterioration SIP satisfy the area’s obligations for maintenance 

of the 2008 NAAQS under § 7410(a)(1) of the Clean Air Act. 

80 Fed. Reg. at 12,301, 12,314. Environmental Petitioners 

argue the Prevention of Significant Deterioration SIP is the sole 

maintenance plan requirement for the 2008 NAAQS, and it
29

only addresses pollution from very large sources. According 

to Environmental Petitioners, the EPA has no statutory 

authority to waive the § 7410(a)(1) maintenance requirement. 

The EPA justified its rule on the ground that orphan 

maintenance areas have already been redesignated to 

attainment for the 1997 NAAQS and designated attainment for 

the more stringent 2008 NAAQS. 80 Fed. Reg. at 12,301. 

According to the EPA, “[a]ny further [§ 7410(a)(1)] 

maintenance plan requirement under the 2008 . . . NAAQS 

would be unnecessarily burdensome.” Id. Although the 

§ 7505a(a) maintenance plans for orphan maintenance areas 

“were established for maintenance of the 1997 . . . 

NAAQS, . . . they also provide a foundation for maintenance

of the 2008 . . . NAAQS, which, in combination with other 

active requirements for the 2008 ozone NAAQS, contribute to 

maintenance of the new standard.” Id. The Final Rule 

explained that “no additional measures beyond the prior 

[§ 7505a(a)] maintenance plans and the PSD plans for the 2008 

[NAAQS] should be necessary to provide for maintenance in 

those areas.” Id.

We previously addressed the alleged waiver of the 

§ 7410(a)(1) maintenance requirement with respect to orphan 

nonattainment areas. See Section IV.B.1(d), supra. As we 

explained, § 7410(a)(1) does not provide clear requirements as 

to what SIPs must include in order to comply with the

§ 7410(a)(1) maintenance requirement beyond the criteria laid 

out in § 7410(a)(2). As with orphan nonattainment areas, with 

respect to orphan maintenance areas, the EPA adequately 

explained why no additional measures beyond the § 7505a(a)

maintenance plans and the Prevention of Significant 

Deterioration plans for the 2008 NAAQS are necessary to 

provide for maintenance of the 2008 NAAQS. Therefore, we 

deny Environmental Petitioners’ petition with respect to the 
30

§ 7410(a)(1) maintenance requirement’s application to 

“orphan maintenance areas.” 

3. Elimination of Second Maintenance Plan

Environmental Petitioners challenge the Final Rule’s 

elimination of the requirement that orphan maintenance areas 

prepare a second maintenance plan under § 7505a(b). 80 Fed. 

Reg. at 12,301. Section 7505a(b) provides that “8 years after 

redesignation of any area as an attainment area,” states “shall 

submit . . . an additional revision of the” maintenance plan “for

10 years after the expiration of the 10-year period referred to in 

subsection (a).” The EPA argues that the requirement for a 

second 10-year maintenance plan is based on an area’s 

designation status under an operative NAAQS. When the 1997 

NAAQS was revoked, the orphan maintenance areas’

designations as maintenance under the 1997 NAAQS were

revoked as well. 

The statutory requirement for a second maintenance plan 

is unambiguous. § 7505a(b). And the Clean Air Act clearly 

contemplates new NAAQS being promulgated within eight 

years of an area’s redesignation to attainment because the 

statute requires the EPA to review NAAQS every five years 

and to “promulgate such new standards as may be appropriate.” 

§ 7409(d)(1). Therefore, the revocation of the old NAAQS 

does not waive the unambiguous requirement for second 

maintenance plans under § 7505a(b). Accordingly, we grant 

Environmental Petitioners’ petition and vacate the Final Rule 

provision waiving the second 10-year maintenance plan for 

“orphan maintenance areas.” 
31

V. Conclusion

For the reasons set forth above, we deny South Coast’s 

petition for review and grant in part and deny in part the 

Environmental Petitioners’ petition. Specifically, we grant 

Environmental Petitioners’ petition and vacate as to (1) waiver 

of the statutory attainment deadlines associated with the 1997 

NAAQS; (2) removal of New Source Review and conformity 

controls from orphan nonattainment areas; (3) grant of 

permission to states to move anti-backsliding requirements for 

orphan nonattainment areas to their list of contingency 

measures based on initial 2008 designations; (4) waiver of the 

requirement that states adopt outstanding applicable 

requirements for the revoked 1997 NAAQS; (5) waiver of the 

§ 7505a(a) maintenance plan requirement for orphan 

nonattainment areas; (6) creation of the “redesignation 

substitute”; (7) creation of an alternative baseline year option; 

(8) elimination of transportation conformity in orphan 

maintenance areas; and (9) waiver of the requirement for a 

second 10-year maintenance plan for orphan maintenance 

areas. In all other respects, Environmental Petitioners’ petition 

is denied.

 

So ordered.